code: def testDFSIter(self):
      g = Graph.Tree(10, 2)
      vs = [v.index for v in g.dfsiter(0)]
      self.assertEqual(vs, [0, 1, 3, 7, 8, 4, 9, 2, 5, 6])
      vs = [(v.index, d, p) for v, d, p in g.dfsiter(0, advanced=True)]
      vs = [(v, d, p.index) for v, d, p in vs if p is not None]
      self.assertEqual(
          vs,
          [
              (1, 1, 0),
              (3, 2, 1),
              (7, 3, 3),
              (8, 3, 3),
              (4, 2, 1),
              (9, 3, 4),
              (2, 1, 0),
              (5, 2, 2),
              (6, 2, 2),
          ],
      )
  
file_path: python-igraph/tests/test_iterators.py
imports: import unittest
  from igraph import Graph
label_desc: Use image node_id 4 for calling the IteratorTests obj's underlying member method code with example usage: obj.testDFSIter() without return types